Batteries for use in cardiac pacer devices, watches and the like which take advantage of electrochemical systems in which the depolarizer is a charge transfer complex and the anodes are various metals such as lithium have become well known. Illustrative with such batteries are U.S. Pat. Nos. 3,653,966; 3,660,163; 3,674,562; 3,723,183; 3,817,791; 3,874,929; 3,937,635; 3,957,533; 4,049,890; 4,072,803; 4,148,975 and U.S. Pat. No. (Ser. No. 896,639, filed Apr. 17, 1978). The lithium halide batteries disclosed in U.S. Pat. Nos. 3,660,163 and 3,674,562 utilize charge transfer complexes mixed with amounts in excess of stoichiometric of iodine. Improvements in lithium halide primary cells are disclosed in U.S. Pat. No. 4,148,975 in which the depolarizer comprises a particulate mixture of iodine, an organic polymer of either poly-2-vinylpyridine or poly-2-vinylquinoline and a charged transfer consisting of the selected organic and iodine. Batteries utilizing these depolarizers have significant advantages over other prior art cells, particularly in terms of shelf life and current capacity. The depolarizers disclosed therein are useful in the present invention.
The aforementioned batteries have normal open circuit voltages of approximately 2.8 volts. Cardiac pacer devices utilizing this type of battery normally employ a voltage doubling circuit to boost the potential to usable levels. These circuits usually include two separate batteries externally connected in series. While the voltage doubling circuit provides satisfactory results in terms of voltage, they are inherently less reliable than a single battery providing the desired voltage.
It is, therefore, an object of the present invention to provide a single battery having the desired open circuit potential without the disadvantages inherent in a circuit having two batteries in series. It is also an object of the present invention to provide a battery with the desired potential which achieves energy efficiency, in terms of volume and mass, over present two battery systems. It is a further object of the present invention to obviate the need for voltage doubling circuits in cardiac pacer devices and to reduce the price of the power source.